Power soarer



ug. 29, 1939. E F. ANDREWS I 2,170,958

POWER SOARER Filed May 14, 1936 4 Smets-Sheet l Aug. 29, 1939.

E. F. ANDREWS POWER SOARER Filed May 14, 1936 4 Sheets-Sheet 2 g. 29, 1939. E, F ANDREWS 2,170,958

Powmz somma Filed May 14, 1936 4 Sheets-Sheet 3 Allg. 29, 1939. E. F ANDEWS 2,170,958

POWER SOARER Filed May 14, 1956 4 Sheets-Sheet 4 Patented Aug. 29, 1939 UNITED STATES PATENT OFFICE 2,170,958 PoWEn'soAaEa Edward F. Andrews, Chicago, Ill.

Application May 14, 1936, Serial N0. 79,789

Claims.

This invention relates to aeroplanes and par ticularly to the type known as power soarers; that is, to aeroplanes having a fiat gliding angle and a low sinking speed, and capable of ascending in rising currents of air of ordinary velocity.

Such a soarer is provided with a relatively small engine, the weight of which is not sulcient to detract greatly from thev essential lsoaring attributes of the machine. The power plant is suilicient to enable the machine `to fly satisfactorily without the aid of rising currents so that, when rising air currents are lost, the engine can be started and the machine own under its own power back to itsbase or to a location in which another rising current suficient for its support is found. In like manner the engine can be employed for leaving the ground and locating rising currents satisfactory for powerless soaring. Upon the location of such currents the motor may be stopped and powerless soaring begun.

One of the difiiculties in making a satisfactory power soarer is the drager air resistance of the propellers and parts of the power plant during soaring flight when the engine is not in use. In a power soarer having a relatively low sinking speed the forward speed is not high and at low speeds the propelling means must have a large disk area to secure satisfactory propeller eiilciency. The large size of the propellers makes their drag great if exposed when not being used, and likewise increases the diiiiculty of satisfactorily housing them. l

According to the present invention these difficulties are overcome by housing the propellers within the wings in such a way as to permit the normal functioning of the wing during soaring flight unimpaired by an appreciable drag or other undesired effects from the idle propellers.

While the invention is directed `primarily toward the reduction of propeller and power plant resistance in power soarers it is also applicable to aeropl'anes of other types, as, for instance, multi-motor planes, one propeller of which could be housed if its motor should stop, thus decreasing the resistance and improving the 'performance of the plane while being driven by the remaining motors and propellers. The invention is, of course,` applicable.to power soarers utilizing `a single propeller or a plurality of propellers.

The invention will readily be understood from the following description of preferred embodiments thereof, taken in vconjunction with the accompanying drawings in which 'i Fig. 1 'is an elevational view of a power soarer embodying my invention;

Fig. 2 is a fragmentary elevational view on a Fig. 5 is a sectional view through the wing, taken on the line 5 5 of Fig. 4, this view being on a somewhat larger scale;

Fig. 6 is a view similar to Fig-5 taken on the line 6-6 of Fig. 4;

Fig. 'I is a sectional detail view taken on the line 1--1 of Fig. 3;

Fig. 8 is a sectional detail view taken on the line 8 2 of Fig. 5;

Fig. 9 is a sectional plan view taken on the line 9-9 of Fig. 6;

Fig. 10 is a sectional plan detail view taken on the line il-IO of Fig. 5;

Fig. 11 is a fragmentary sectional elevational View taken on the line Ii-II of Fig. 10;

Fig. 12 is a fragmentary plan view showing a further embodiment of my invention;

Fig. 13 is a fragmentary sectional detail showing a still further `embodiment of my invention;

Fig. 14 is a fragmentary plan view showing a, further embodiment of my invention;

Fig. 15 is a sectional detail view taken on 4the line IB- of Fig. 14;

Fig. 16 is a similar view taken on the line I6|6 of Fig. 14;

Fig. 17 is a sectional view similar to Fig. 16 showing the device in a different state of adjustment; and

Fig, 18 is a fragmentary detail view showing the manner in which certain controls may be connected together. y

Referring to the drawings, and more particularly to Figs. 1 and 3, the power soarer comprises a conventional' fuselage 20 provided with eleva-4 tors, rudder, etc., and provided with a wing structure 2|. The wing structure is preferably located at the top of the fuselagefand the passenger preferably sits in front of the wing, as suggested in Fig. 3. The landing gear comprises wheels 22 and 23 on the major axis of the fuselage, and also stabilizing wheels 24 at some distance at each sideof the fuselage.

` The engine may suitably be a two cylinder, horizontal engine 25, mounted behind the pilot, `and is preferably near the center of pressure of the wing. This engine may be quite small and f it can be located within the wing. It may be provided with a pulley 26 and it may be connected to a radiator 21 which is located in the plane l' of the wing rearwardly of the engine and of the two propellers 28. These propellers are mounted on shafts 2! which are provided with pulleys Il. 'I'he shafts 29 are rotatably mounted in bearings Il within the wing structure. 'Ihe pulleys Il are located within the Wing structure and arein alignment with the pulley, 26. V-belts tion of the propellers, as shown at 33 on the right-hand side of Fig. 4. The belts 3|' are normally maintained taut by means of idler pulleys 35 carried by cranks 36 pivotally mounted at 3l, as best shown in Figs. l0 and ll.

The cranks 35 are normally pulled by springs 36a. so as to apply the idlers 35 forcibly against the belts 3|. A cable 38, secured to one of the cranks 36 and passing over pulleys 33 is connected to a drum 4|) which may be actuated by a hand crank 4| within reach of the operator. The drum 40 may be heldin desired position by a pawl 4| a.. It will be seen that when the crank 4I is rotated, the associated idler 35 is lifted out of contact with its belt 3| so that this belt may slip over its pulley 30 when that pulley is locked and the engine is turned over slightly to move the other propeller to locking position. A drum 40 and cable 38 may be provided for one or both belts 3l and a single drum 40 may ,be arranged to release both cables simultaneously, as shown in Fig. 18.

Each pulley 30 is provided. with one or two openings 42 which are adapted to be entered by a latch 43. 'Ihe latch is provided with a spring 44 which normally tends to pull the latch 43 out of engagement with theopening 42. 'I'he latch 43 may be movedv towards the pulley 3G against the action of the spring 44 by means of a cable 45 which passes-over pulleys 46 to a position adjacent the operator.

Each cord 45 contains a spring 41 and at the end, near the operator, it is provided with a ring 48 which may be engaged by a hook 49. I'he arrangement is such that when the operator pulls the cord 45 and passes the ring 48 into hooking engagement with the hook 49, .the latch 43 is resiliently pulled towards the pulley 30. When the pulley 30 is rotated suiliciently to bring one of the openings 42 into registry with the latch 43, that latch enters the opening 42 and prevents further rotation of the pulley 30. This position of the pulley 30 corresponds to the location of the associated propeller 28 in a'position parallel to the wing span; that is, this propeller is located within the confines of the Wing shape. As shown in Fig. 18 the cords 45 may be connected to the drum` 40 so that rotation of the crank 4| releases the: tension of the belts 3| and renders the latches 43 operative.

The engine may be turned over by means of a pull starter 5|) located adjacent the operator, as shown in Fig. 3. The method of locating the propellers is` as follows: The ignition being turned off, the crank 4| is turned, pulling the cables 38 and 45, thus removing the pressure of the idlers 35 from the belts 3| and also pulling the latches 43 against the pulleys 30. One of the propellers may move into latched position automatically and the other propeller may also move into proper position for latching, owing to the air stream o-n the propellers. However, the friction between belts 3| and pulleys 26 and'30 may be great enough to stop this propeller at some other position. In vthis case the engine is turned by means of a pull starter 50 until the opening 42 in the pulley 30 of the unlocked propeller registers with its latch 43, when it is automatically pellers.

armena it is merely necessary for the operator to release the pawl lil on drum lill and rotate the crank 4l or allow it to rotate in the opposite direction from that which was used for locking the pro- The latches i3 are withdrawn from the openings 42 by action of the springs @d and the idlers 35 are forced against belts 3l by the springs 3l.

Means are provided whereby a practically complete wing with a substantially unbroken surface is provided after the propellers have thus been stowed within the normal outline of the wing. For this purpose I provide a ap 5l which can be best understood from its dotted line position shown in Fig. 6. This flap comprises a rigid sheet, the forward ends of which are provided with trunnions 52. These trunnions are adapted to slide in a pair of slotted rails 53, one of which is shown in Fig. 8. The slotted rails 53 are located on the underside of the wing. At its rear end the flap 5| carries a trailing edge forming member 54 which conforms to the general outline of the tail of the wing, as best seen in Fig. 5, where this iap is in soaring position. When the machine is adapted for use as a power soarer, the ap 5| is moved into its former position, shown in full lines in Fig. 6, and the trailing edge forming member is housed within the wing. y h

The forming member 54 is provided with a longitudinal recess 55 to enable it to clear the shaft 29 when in power-operated condition; that is, the'condition shown in full lines in Fig. 6. When the machine is in this condition, a section of the radiator 2l is located in the slip stream of each propeller. 'I'he trailing edge forming member 54 is provided with transverse recesses 56 to accommodate one of the cylinders of the engine 25 when the forming member 54 is stowed for power operation. Each radiator section 2l preferably carries a rearwardly extendingplate 51 which covers the opening 56 when the machine 'is' arranged for soaringwithout power. This condition of the machine is illustrated in Fig. 5.

It may here be pointed out that the intermediate position of adjustment of the iiap 5|, as shown in dotted lines in Fig. 4, is particularly advan tageous and is used during landing, since in this position the iiap 5| exercises a strong braking effect as well as increasing the lift coeicient. It will be understood that I provide a flap 5| on each side of the fuselage 20 and that leach ilap can be arranged to ll the vacant space 33 behind each propeller 28.

It may here be noted that the condition shown in Fig. 4 cannot be obtained by the preferred embodiment of the invention since I prefer to actuate both flaps 5| simultaneously by the same mechanism, this showing being used for purposes of illustration. Near its rear end each flap 5| has pivotally connected thereto a link 56, which link is rigidly connected to a shaft 59 which extends the full length of. the two flaps, and the intermediate portion of the wing between these two flaps. y

The shaft 59 carries a worm gear Ellwhich can 'be operated in either direction by worm 6|. The

the normal confines or outline of the wing prole, and that the underside of the wing presents an uninterrupted surface which extends 'below and beyond both propellers 28.

The invention is capable of other embodiments. Thus. in Fig. l2 I have shown a propeller 28 mounted for rotation in a slot 64 in the wing structure. 'I'he slot is relatively narrow adjacent the center of the propeller, but its opposite ends are enlarged so asto provide substantial clearance between wing and propeller to reduce losses where the peripheral speed of the propeller past the wing is high. Adjacent the upper and/or lower surfaces of the wing, I pivotally mount leaves 65 which are normally pulled away from the slot by means of springs 66. Cables 61 are attached to the rigid plate 'i5 and these cables pass over suitable pulleys and are connected to a singie cable 68. It will be readily understood that when the cable 68 is pulled, the plates 65 are illed together so as to effectively close the slot In the embodiment of the invention shown in Fig. 13, I locate within the wide portions of the slot 64 bellows 69. These bellows are made of resilient material such as rubber, and adapted, when expanded, to conform closely to the natural outline of the wing structure. A pipe 10 communicates with the interior of these bellows and extends forwardly to a position where the operator may supply air for the inflation of the bellows. Thus the operator may supply air from a pump, bellows or compression reservoir (not shown) through the pipe 10 to effect the inflation of the bellows 69. The bellows i9 may be maintained inflated by means of a suitable valve (not shown) In Figs. 14 to 1'1 inclusive I disclose a further modification of the invention according to which AI provide on the upper and lower surface of the wing an extensibe sheet 12 such as rubber. Within the sheet 12 and adjacent its rear edge is embedded a strengthening rib 13 which makes this edge rigid. As shown in Fig. 14, each sheet 12 extends beyond the ends of the slot 6I. Cables 14 are connected near each end of the rib 13 and pass through slots 15 into the interior of the tail portion of the wing. Within that tail portion the cables 14 pass over pulleys 16 and the cables from each side are connected together to two cables 11 which extend to a position adjacent the operator. It will be readily understood that when the two cables 11 are pulled by the operator, the two elastic sheets 12 are extended so as to cover completely both sides of the slots 6I. It may be here noted thatin this modification a very substantial reduction in air resistance may-'beV effected by merely locking the propeller in the slot in a position parallel with the span of the wing leaving the slot uncovered, further reduction in air resistance being obtained by Dloper shaping of the edges of the slot 64 and edges oi propeller 28. `It will be understood, of course, that in connection with the modifications shown in Figs. 12 to 17 inclusive, the propellers are located in the slots 6I within the natural outline of the wing in the same way 'as in the embodiment of the invention illustrated in Figs. 1 to 1l inclusive.

` Although my invention has been described in connection with the specific details of a preferred embodiment thereof, it mu'st be understood that such details are not intended to be limitative of the invention `except in so far as set forth in the accompanying claims. Having thus described my invention, I declare that what I desire to claimis:

1. In an aeroplane having a wing, a motor, a propeller operatively connected to the motor and having a position within the general upper and lower surface lines of the wing in front of a rear portion of the Wing, said rear portion of the wing behind said propeller being movable, and means for moving said rear portion out of normal position and stowing it within the forward part of the wing for propeller operation.

2. In an aeroplane having a wing, a motor, a propeller operatively connected to the motor and having a position within the general upper and lower surface lines of `the wing in front of a rear portion of the Wing, said rear portion of the wing behind saidl propeller being movable, means for moving said rear portion out of normal position and stowing it within the forward part of the wing for propeller operation, and a closure sheet member connected to said trailing rear portion extending below the propellerwhen it is stowed in said position,

3. Inv an aeroplane having a wing, a motor, a

4'propeller operatively connected thereto, said Wing having a slot, extending from its upper to its lower surface, in which the propeller operates, said propeller being operable in a plane transverse to the plane of the wing and having a position within the general upper and lower wing surfaces, and means capable of substantially completing at least one of said surfaces when the propeller is thus positioned.

4. In an aeroplane having a wing, a motor, a

A propeller operatively connected thereto, said propeller having a position within the general upper and lower Wing surfaces and in front ofa rear portion of the wing, said rear portion of the wing behind said propeller being movable, a forwardly extending sheet member carrying said rear portion, means slidably supporting the forward end of said sheet member on a surface of the wing, a transverse shaft in the wing, links rigidly carried thereby, said links being pivotally connected to said rear portion, whereby the rear portion may be swung from a position behind to a position in frolnt of the propeller, the wing being recessed in 4front of the propeller to receive it, the recess being covered b y the sheet member in its rearmost position.

5. In an aeroplane having a4 wing, a motor, a propeller operatively connected thereto, said wing having a slot, extending from its top surface to its lower surface, in which said propeller operates in a plane transverse tothe plane of the wing, said propeller having a position within the general upper and lower wing surfaces, and an elastic covering capable of being extended over the slot substantially to complete at least one of said surfaces when the propeller is thus positioned.

6. In an aeroplane having a wing, a motor, a propeller operatively connected thereto, said wing having a slot in which said propeller operates, said propeller having a position within the general upper and lower wing surfaces, and inflatable members in said slots substantially completing said surfaces when the propeller is in said pootalplates adapted to be swung over said slot sub-` stantially completing at least one of said surfaces when the propeller is in said position.

8. In an aeroplane having a wing, a motor, two propellers operable within the wing profile, belts connecting said motor to said propellers, means for decreasing the tension of at least one belt, means for locking each propeller in a position wholly within the wing prole, and means for turning over the motor whereby both propellers may be locked in position. e

9. In an aeroplanehaving a wing, amotor, two propellers operable within the wing profile, belts connecting .said motor to said propellers, means for decreasing the tension of at least one belt, a latch for each propeller adapted to lock the propellers wholly within the wing profile, said latches being normally biased out of locking position, manual means operative to bias said latches into operative position, and means for turning over the motor whereby both propellers may be locked in position.

10. In an aeroplane having a wing, a motor, two propellers operable within the wing profile,

, belts connecting said motor to said propellers,

belts connecting said motorto said propellers,

means for decreasing the tension of at least one belt, a latch for each propeller adapted to lock the propellers wholly within the wing profile, said latches being normally biased out of locking position, manual means operative to bias said latches into operative position, means for turning over :he motor whereby both propellers may be locked in position, and movable means substantially completing the wing surfaces when the propellers are locked in position. l

12. In an aeroplane having a wing, a propeller rotatable in a fixed plane transverse to the plane of the wing and adapted to be housed within the outline of the wing, a closure sheet member on the underside of the wing movable into and out of a position to house said propeller, and means for positioning said sheet member so that it projects in a downward and rearward direction from the wing.

13. In an aeroplane having a Wing, an engine,

cooling means therefor within the outline of said wing, a propeller operatively connected to said engine, mounted within the outline of the wing,

and operable ahead of said cooling means to direct air over the cooling means, said propeller being operable in a xed plane transverse to the plane of the wing, and a movable closure member adapted in one position to house said pro-r` peller and said cooling means.

14. In an airplane, a fuselage, a wing extending out on each side thereof, a main wheel located substantially on the vertical plane of the major axis of the fuselage behind the center of gravity, a wheel on the same axis located. near the front of the fuselageand stabilizing wheels yieldably carried by the wing 'on each side of the fuselage.

15. In `an airplane having a wing, avmotor, a propeller-operatively connected to the motor, said propeller having a positionwithin the genarmate eral upper and lower surface lines of the wing in front of a rear portion of the wing, said rear portion of the wing behind said propeller being movable, the part of the wing before the propeller being provided with a recess, means for moving said rear portion out of normal position and stowing it within said recess for propeller operation, and a closure member connected to said rear portion extending below the propeller and below the recess when the propeller is stowed in said position.

16. In a wing of airfoil section, in combination, a rear flap having substantial vertical thickness, the lower surface of said wing being provided with a recess for housing said flap when retracted, slidable vmeans connecting the forward end of said flap to said wing, a link connecting the rear of said ilap to the rear of saidwing, and meansfor rotating said link around an axis at the rear of said wingto extend and retract said flap. l

17. In an airplane, a fuselage, a wing extending out oneach side thereof from an elevated position on the fuselage, a pair of propellers` mounted on thewlng, one on each side of the fuselage, main wheel means located substan- 1 tially on the vertical plane of the major axis of the fuselage behind the centerl of gravity, a wheel substantially on the same plane located near the front of the fuselage, wheel mounting means extending downwardly from the wing on each sideof the fuselage, and stabilizing wheels yieldably mounted on the wing by said wheel mounting means.

18. In an airplane, a fuselage, a wing extending out on each side thereof at an elevated position, main wheel means located substantially on the vertical plane of the major axis of the fuselage behind the center of gravity, a wheel substantially on the same plane located near the front of the fuselage, wheel carrying means extending downwardly from the wing on each side of the fuselage, stabilizing wheels yieidably mounted on the wing by said wheel mounting means, and struts extending from a -low position on the fuselage toisaid wing adjacent the point of attachment of said mounting means thereto.

19. In an airplane, in combination, a fuselage, a wing of airfoil section extending on either side thereof, a flap having substantial vertical thickness on said Wing, on each side of the fuselage, the lower surface of said wing being provided with recesses for housing said flaps when retracted, supporting means, including links connecting the flaps to said wing, means passing into the fuselage for rotating a plurality of links on both sidesof the fuselage around an axis in said wing to project and retract said flaps, and manually controlled means for actuating said means passing into the fuselage.

20. In an airplane, in combination, a fuselage, a wing of airfoil section extending on either side -thereof, a flap forming substantially the entire thickness of the trailing portion of the wing and the trailing edge, the lower surface of said wing being provided with a recess for housing said flap within-the wing contour when retracted, supporting means connecting the flap to said wing whereby it may be projected downwardly from the wing and moved bodily in relation thereto from said trailing edge forming position to said housed position, and means for actuating said connecting means to project `and retract said nap.

. EDWARD F. ANDREWS. 

